Troubleshooting Guide: Error 307 – Invalid Byte Range File Lock Failure
Why This Error Happens
Error 307 occurs when an application requests a byte-range file lock that falls outside the actual boundaries of the file, or when the specified range overlaps with an already-locked region held by another process. This typically stems from a corrupted or truncated file, a mismatch between the file’s reported size and its actual on-disk size (often due to abrupt process termination or interrupted writes), or a faulty third-party filter driver (such as antivirus or backup software) that intercepts and mismanages I/O requests. Network file systems (SMB/NFS shares) are especially prone to this issue when latency or caching causes stale file metadata to be used during the lock request.
Step-by-Step Resolution Guide
- Check File Integrity via System File Checker
Open Command Prompt as Administrator and run:
sfc /scannow
Follow up with:
DISM /Online /Cleanup-Image /RestoreHealth
This repairs corrupted system files that may be triggering invalid lock requests.
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Identify and Close the Locking Process
Use Resource Monitor (resmon.exe) → CPU tab → Associated Handles, and search for the problematic file name. Identify which process holds an active lock and close it gracefully, or terminate it via Task Manager if unresponsive. -
Disable Third-Party Filter Drivers Temporarily
Boot into Clean Boot mode (msconfig→ Services tab → check “Hide all Microsoft services” → Disable all) to rule out antivirus or backup software filter drivers interfering with file I/O. If the error disappears, update or reinstall the conflicting software. -
Verify File Size Consistency on Network Shares
If the file resides on a mapped network drive, disconnect and remap it:
net use Z: /delete
net use Z: \\ServerName\ShareName /persistent:yes
This forces Windows to refresh cached file metadata, resolving mismatches between reported and actual file size.
- Update Storage and Network Drivers
Go to Settings → Windows Update → Advanced Options → Optional Updates → Driver Updates, and install any pending updates for storage controllers or network adapters, as outdated drivers can mishandle lock range calculations.
Alternative or Verification Steps
- Verify the fix: Reopen the affected file/application and monitor Event Viewer (
eventvwr.msc→ Windows Logs → Application) to confirm Error 307 no longer appears during file operations. - Alternative fix: If the issue persists only on a specific file, copy its contents to a newly created file and delete the original — this bypasses any residual corrupted lock metadata tied to the old file’s file table entry.